[Qemu-devel] [RFC PATCH v2 0/4] simpletrace : support var num of args and strings.

[Harsh Prateek Bora <harsh@linux.vnet.ibm.com>]

Existing simple trace can log upto 6 args per trace event and does not
support strings in trace record format. Introducing new trace format as
discussed earlier on list to support variable number/size of arguments.
(Ref: http://lists.gnu.org/archive/html/qemu-devel/2011-11/msg03426.html)

Basic testing of this patch is successful. Stress testing not yet done.

Apply patches, then run:

make distclean
./configure with --enable-trace-backend=simple
make
sudo make install

Sample tracelog showing strings support:
[harsh@harshbora v9fs]$ scripts/simpletrace.py trace-events trace-23261
v9fs_version 0.000 tag=65535 id=100 msize=8192 version=9P2000.L
v9fs_version_return 17.530 tag=65535 id=100 msize=8192 version=9P2000.L
v9fs_attach 180.121 tag=1 id=104 fid=0 afid=18446744073709551615
uname=nobody aname=


Note: LTTng ust backend is broken in upstream qemu, therefore tracetool.py
doesnt support ust backend as of now. IIUC, ust's trace event APIs are under
development and not yet stable.

Version History:

v2:
- Updated tracetool.py to support nop, stderr, dtrace backend

v1:
- Working protoype with tracetool.py converted only for simpletrace backend

Harsh Prateek Bora (4):
  Converting tracetool.sh to tracetool.py
  Makefile and configure changes for tracetool.py
  simpletrace-v2: Handle variable number/size of elements per trace
    record.
  simpletrace.py: updated log reader script to handle new log format

 Makefile.objs          |    6 +-
 Makefile.target        |   10 +-
 configure              |    4 +-
 monitor.c              |    2 +-
 scripts/simpletrace.py |  110 ++++++++++-
 scripts/tracetool.py   |  505 ++++++++++++++++++++++++++++++++++++++++++++++++
 trace/simple.c         |  178 ++++++-----------
 trace/simple.h         |   31 +++-
 8 files changed, 702 insertions(+), 144 deletions(-)
 create mode 100755 scripts/tracetool.py